Glossary of Terms abiotic — non-living environmental factors, such as light, wind, rock, soil, and water. abundance — the number of individuals of a given species in a population. active management — meeting desired forest objectives and future conditions using various management practices to affect growth, density, health, harvest, regeneration, etc. Active forest management may include planning, timber harvesting, tree planting, thinning, tending, weed control, road and trail maintenance, and other activities for improving wildlife habitat. adjacent housing — any dwelling that is close to, or shares a common border with forest. advanced regeneration — An established understorey consisting of seedlings and saplings. aerial foragers — birds that feed by capturing prey in the air. aerial insectivore — species that specialize on flying insects for food (such as flycatchers, swifts, and swallows). age class — a category that describes trees, or stands of a similar age. The age class division separates trees of different species into classes based on a similar age, often 20-year intervals. area sensitive — species that require large or continuous patches of natural habitat. Responses will vary depending on the level of sensitivity; some species will be absent from forest patches of a particular size, others will be less common, or show poor productivity in smaller forest fragments. avian — relates tobirds. bark gleaners — species that pick insects from the surface and crevices of tree bark, twigs, and branches. barrier — something that prevents or limits movement of an organism. basal area — the cross-sectional area of a tree measured at 1.3 metres above the ground (breast height). Typically expressed in m 2 /ha, based on the measure of all the trees in a stand. baseline — an imaginary line or standard by which things are measured or compared. best management — defined as the most efficient (least amount of effort) and effective (best results) way of accomplishing a task, based on procedures that have proven themselves over time for large numbers of people. Forestry best management practices conserve soil, water, wildlife, and forest resources over the long term. biodiversity or biological diversity — the number and variety of species of plant and animal life within a region. This includes differences within species (at the gene level), between species, and within and amongst ecosystems. A high level of diversity within a species, or genetic diversity, helps the species to survive massive changes in climate and the environment. Ecosystems with a high level of diversity support a greater number of life forms are more stable, and resilient to change. biomass — the mass of organic matter in a given area. It also refers to plant matter burned as fuel. biotic — Living components of the environment or ecosystem such as plants and animals. blowdown — an area where trees have fallen due to wind. blowsands — open areas of blowing sand that occurs when the vegetation is removed and the topsoil erodes. These areas have dry and infertile soil susceptible to wind erosion. boreal forest — the largest, most northern forest region in Ontario, dominated by conifer species like spruce and jack pine. This forest region occurs in a wide band from Newfoundlandto Alaska, from Hudson Bay, south to the north shores of Lake Superior. The boreal forest climate includes short warm summers and long cold winters. breeding — the time when animals are producing offspring or young. For birds, this corresponds to the period when they are building nests and raising young. breeding cycle — the timeframe of reproductive activity from initial courtship and pair formation through nesting to the final independence of the young. For birds, this typically begins with males finding a territory, followed by attracting a mate, copulation, nest building, nesting (including egg-laying, incubation, hatching, feeding of nestlings), to parental care of young that have left the nest until they are able to care for themselves. breeding ground — the place where animals breed. breeding population — a group of organisms whose choose mates from within the group. Often the breeding population is within an individual woodlot. breeding range — the geographical area where breeding activities occur. For non-migratory birds or permanent residents, their summer breeding range will overlap their winter range. For migratory birds, their winter range is hundreds or thousands of kilometres away. breeding season — the period of time in which species breed, usually when favourable conditions, abundant food, and water are present. Different species of animal and birds have different breeding seasons according to their particular requirements and food availability. For most bird species in southern Ontario, this occurs between April and August. breeding site — the microhabitatin which breeding occurs. For example, vernal pools are breeding sites for frogs. broadleaf — a class of trees that have broad, flat leaves of many different shapes; most are deciduous; also called hardwood, because most broad-leaved trees have harder wood than do conifers. Examples include oak, hickory, maple, and ash. brood — a group of young produced or hatched at one time from a single set of parents. Some birds mate and have more than one group of young in a season. Glossary of Terms 89